Refrigerant flow control apparatus



Jan. 5, 1965 D. D. WILE ETAL 3,163,998

REFRIGERANT FLOW CONTROL APPARATUS Filed Sept. 6, 1962 2 Sheets-Sheet 1 65 34 FIG-l 28 fiEv r-E |5 EVAPORATOR l] CONDENSER RECEIVER EI M COMPRESSQR W "jlll' 1 IN VEN TORS DANIEL D. WILE SHIZUO R.ADACHI m AT TORNEYS 1965 D. D. WILE ETAL 3,163,998

REFRIGERANT FLOW CONTROL APPARATUS Filed Sept. 6. 1962 2 Sheets-Sheet 2 FIG.2

DANIEL D. WILE SHIZUO R. ADACHI I BY a 0 El E N M -8- il l I ATTORNEYS I INVENTORS United States Patent Ofilice 3,163,998 Patented Jan. 5, 1965 3,163,998 REFRIGERANT FLOW CGNTRGL APPARATUS Daniel D. Wile, Whittier, and Shizuo R. Adachi, Glendale, Caiif., assignors to Recoid Corporation, Los Angeles, Calif, a corporation of California Filed Sept. 6, 1962, Ser. No. 221,771 2 Claims. (Cl. 62-278) This invention relates to refrigerating apparatus and more particularly to improvements in the manner returning gaseous and liquid refrigerant to the compressor of such apparatus during hot gas defrosting operation.

The apparatus of the invention is particularly useful in connection with refrigerating systems which employ hot gas defrosting. In such systems, portions of the hot gases passing through the evaporator or refrigerator coil are condensed to form slugs of liquid refrigerant, which, if permitted to pass into the compressor, results in damage to the apparatus.

The principal object of the present invention is the pro vision of apparatus which will eliminate the possibility of damage to the refrigerating system by large quantities of liquid refrigerant discharged from the evaporator or refrigerating coil.

A further object of the invention is to provide an apparatus of the indicated type which will permit the unrestricted return of gaseous refrigerant from the evaporator to the compressor and a controlled return of liquid refrigerant.

A further object of the present invention is to provide a simple and inexpensive defrosting arrangement which may be integrated with the conventional refrigerating system.

Another object of this invention is to provide in a refrigerating system, means which will return liquid refrigerant to the compressor at a controlled rate when the refrigerating system is being utilized for the defrosting of the evaporator thereof through the delivery of hot refrigerant from the compressor to the evaporator, while the compressor is still in operation,

Still another object of the invention is the provision of the device of the indicated type which is simple and economic in construction, and which provides a heating means for vaporizing the liquid refrigerant which may be present during normal refrigeration operation and effects a controlled rate of return of liquid refrigerant flowing back from the evaporator to the compressor.

A further object of the invention is the provision of a device of the indicated type which is compact, thereby adapting it for close installations and which is further characterized by the complete absence of any moving parts thereby adapting it for continuous operation over extended periods of time without service of any kind.

These and other objects and advantages of the invention will become apparent from the following detailed description, taken with the accompanying drawings, wherein:

FIGURE 1 is. a diagrammatic view of refrigerating system employing the apparatus of the present invention. FIGURE'Z is a vertical cross sectional view of one form'of the apparatus in accordance with the invention. FIGURE 3 is an end view of the apparatus shown from the inlet portionthereof.

FIGURE 4 is an end view of the apparatus shown from the outlet portion thereof.

In the preferred embodiment of the invention, FIG- URE 1 illustrates a refrigeration system in which the factors embodying the invention have been diagrammati-' cally incorporated, and where hot gas from the compressor may be delivered directly to the coiling or conduits of the evaporator when desired to effect defrosting of the coil of surfaces of the evaporator. During this operation, the evaporator functions in a manner similar to the condenser in the normal refrigeration cycle so that the gaseous refrigerant used to effect the defrosting is condensed, or at least a portion thereof may be condensed, depending on the quantity of heat required to raise the temperature of the evaporator surface sufiiciently to effect the defrosting operation. The condensed refrigerant, in accordance with the invention, is metered, or returned at a controlled rate to the compressor and at such a rate as may be handled by the compressor without damage thereto, avoiding the passing to the compressor of large quantities of refrigerant which would be detrimental thereto.

Referring now to FIGURE 1, during the refrigeration cycle, the compressor is designated by figure 10, and may be of any of the conventional forms. The compressor 10 compresses the gaseous refrigerant and forces it into the line 20. The refrigerant then passes into the condenser 12 and into receiver 14. From the receiver, the hot liquid refrigerant flows through line 24 and into the refrigerant flow retarding unit 34, exchanging heat therein, and then on into line 26 to expansion valve 16. From the expansion valve, the liquid refrigerant expands and passes into evaporator 18 whereupon it becomes evaporated and performs the cooling operation. From the evaporator the refrigerant passes into the evaporator outlet line 28, and into the refrigerant flow retarding unit 34. In the refrigerant flow retarding unit, the gaseous refrigerant and any liquid refrigerant which during normal refrigeration operation is present is retarded and heated and the gaseous refrigerant passes into the low pressure, or suction line 22; the refrigerant then passes into the compressor 10, and the cycle is repeated.

In accordance with the invention, when frost has accumulated on the surface of the evaporator, the hot gas from the compressor 10 may be by-passed to the evaporator 18 by means of control valve 32 which allows the hot gas refrigerant to pass through line 30 and into the evaporator 18, thus heating the evaporator and removing the frost therefrom. From the evaporator 18, the liquid refrigerant passes through into the evaporator outlet line and into the flow retarding unit 34. Here it is retained and then metered in controlled quantities, into suction line 22; by commingling with gaseous refrigerant which aspirates said liquid refrigerant, said liquid refrigerant, along with gaseous refrigerant flew back to compressor 10. When defrosting is complete, valve 32 is then closed, and the normal refrigerant cycle, as described above,

continues. During this defrosting operation, the pressure 3 During the normal refrigeration cycle, vapor refrigerant flowing from the evaporator through the evaporator outlet line 28, enters the refrigerant flow retarding unit, composed of tank 62, sealed at both ends by cap members 64 and 55, and passes into the discharge segment 38. The vapor refrigerant is heated by coil 36 formed of spiral fin tubing, the heating coil is fed by hot liquid refrigerant from the receiver entering the refrigerating flow retarding unit 34 through receiver line 24, the receiver line enters the refrigerating flow retarding unit and forms a coil around the discharge segment 38. The opposite end of this coil returns the liquid refrigerant through the line 26 to the expansion valve 16. Thus, a means is provided for exchanging heat between the vapor refrigerant and the liquid refrigerant in the high pressureline 20. The gas-refrigerant leaves the discharge segment 38 and flows into the heat exchanger chamber 40 which comprises an outer shell member 44, and an end member 4-2 which is proximate to the terminal portion of discharge segment 38. The refrigerant being discharged by this discharge segment 38, is then discharged. over the heat exchanger coils 3d and is retained by the end of the heat exchanger chamber 42 so that it is forced to flow over the heat exchanger coils and out of the oppositeopen end 46 of the chamber 40 and into the refrigerant separation chamber 48. a

The refrigerant separation chamber 48 is terminated'by a baflle member 59. This first bafiie member 50 has a segment SZremoved from the top thereof. This removed segment"52 leaves an aperture by which the vaporous refrigerant may flow into thefiow control chamber 54.'

Also provided in the refrigerant separation chamber 48 is a screen member'56 which protects a metering aperture or orifice 58, located in the lower portionof the first baflle member 50. The screen member 564s provided for preventing the ingress of extraneous matter into the orifice 58 from the lowermost region of the refrigerant separation chamber 48. Thus, the aperture 58 which is supported in the bathe member 50 causes a fluid communi-. cation between the refrigerant separation chamber 48, and the flow control chamber 54. I

The refrigerant flow retardingunit is further provided with a second baffie member 55, which terminates the flow control chamber 54 and provides a discharge chamher-60. The second baffle member 55' is provided with an opening 59, which is formed by removing a lower segment ofthe bafile 55, and provides a means for the vaporized refrigerant and metered liquid refrigerant. to enter into the discharge chamber 60, during the defrost cycle.

From this point in the discharge chamber 60, the vapor refrigerant is withdrawn from the refrigerant flow retarding unit 34 and into the compressor suction line 22. During the defrost cycle, the heat exchanger coils 36 become inoperative, and gaseous refrigerant is delivered directly to the evaporator 18, as previously discussed. From the evaporator the liquid refrigeranttpasses into the discharge segment '38, of the flowretarding unit. From the discharge segment the liquid refrigerant passes through the heat exchanger chamber 49, and into the separation chamber 48, here the vaporized or gaseous refrigerant is 1' separatedoff and flows through the removed segment aperture 52' of the first baffle plate 59 and oninto the how control chamber. The liquid refrigerant passes through the screen member 56, and through the aperture 58, the size of this aperture controls the flow of this liquid refrigerant. The combined gaseous and liquid refiigerantthenflowsthrough aperture 59, and oninto the the gaseous refrigerant to'the compressor ata con- I trolled rate which the-compressor can; handle without damage thereto.

While the preferred embodiments of the invention have all been illustrated and described herein, the invention is not to be construed as limited to the specific details disclosed herein, except as included in the following claims.

We claim:

1. In combination with a refrigeration system, including a compressor, a condenser, and an evaporator, means for defrosting said evaporator without shutting off the compressor, said means including: a liquid refrigerant flow retarding unit interposed in the suction line between the evaporator coil and the compressor for retarding liquids in the refrigerant flowing from the evaporator to the compressor during defrosting operations, said unit comprising a tank sealed at both ends by cap members and incorporating first and second baffle members that divide said tank into a separation chamber, a flow control chamber and a discharge chamber, a heat exchanger chamber, with a discharge segment of the evaporator outlet line extending thereto for discharging refrigerant in mingling liquid and vapor form from the evaporator thereinto, a discharge chamber with an intake segment of the compressor suction line connected therein; a metering aperture enclosed with a fine mesh screen member for preventing the ingress of extraneous matter thereinto from the lowermost region of said separation chamber, the outlet of which is supported in said first baflie member in fluid communication with the flow control chamber in consequence whereof liquid ingredients of the refrigerant discharged into said fiow control chamber flow onwardly to the compressor via the intake segment of the suction line; an entrance opening into said flow control chamber for vapors flowing from the separation chamber, said opening being formed in consequence of a segment being removed from said first baffle member at the top thereof; said second baffle member interpolated between said first baffle member and the discharge chamber cap member whereby to form the flow control chamber and discharge chamber said second baffle member including: a body portion provided centrally adjacent to the lowermost region thereof with an opening, formed by the removal of a segment thereof, an annular laterally projecting flange integral with said body portion for mounting the baffle in said tank, said opening formed in said body portion for establishing communication between said flow control chamber and said discharge chamber.

2. In combination with a refrigeration system including a compressor, a condenser, a receiver, an evaporator, and an expansion valve; means for defrosting said evaporator without shutting off the compressor, said means including: a liquid refrigerant flow retarding unit interposed between the compressor suction line and the evaporator outlet line, said unit comprising a tank sealed at both ends by capmembersand incorporating first and second bafile members that divide said tank into a separation chamber, a flow control chamber, and a discharge chamber, a heating chamber with a discharge segment of the evaporator outlet line extending therein, said heating chamber comprising an outer wall terminated at the end proximate to said discharge segment by a cap member, said heating chamber including a heat exchanger coil formed of spiral fin tubing, said heat exchanger coil being circumferentially about said discharge segmentand extending laterally along its length and to the proximate cappedend of said heating chamber, a separation chamber, terminated by the first circular battle member, a vapor entrance formed in said bathe member by removal of the uppermost segment thereof, a metering aperture, enclosed by a fine mesh screen, said aperture supported by the first circular bafile member in the lowermost portion thereof, a second circular baffle member so formed as to provide a'fiow control chamber with said first bafile member, and a discharge chamber between said second baflle member and the discharge end cap member, the second bathe member having an entrance therein, formed by removing a segment from the lowermost portion thereof, the metering aperture providing fluid communication 5 between the refrigerant separation chamber and the flow control chamber, the chamber entrance providing both vapor and liquid communication between the flow control chamber and the discharge chamber, an intake segment of the compressor suction line through said discharge chamber, the metering orifice in the bottom portion of the first batfie member providing a means to control the rate of flow of liquid refrigerant, produced during the defrosting operation, by separating said liquid from the gaseous refrigerant, then returning same along with the gaseous refrigerant at such a rate that the refrigerant may be returned to the compressor in a form that the 6. compressor may recompress the same without damage to the compressor.

References Cited in the file of this patent UNITED STATES PATENTS 1,613,687 Wales Ian. 11, 1927 2,121,253 McGuffey June 21, 1938 2,589,855 Pabst Mar. 18, 1952 2,760,355 Swart Aug. 28, 1956 3,012,414 La Porte Dec. 12, 1961 3,012,415 La Porte Dec. 12, 1961 

1. IN COMBINATION WITH A REFRIGERATION SYSTEM, INCLUDING A COMPRESSOR, A CONDENSER, AND AN EVAPORATOR, MEANS FOR DEFROSTING SAID EVAPORATOR WITHOUT SHUTTING OFF THE COMPRESSOR, SAID MEANS INCLUDING: A LIQUID REFRIGERANT FLOW RETARDING UNIT INTERPOSED IN THE SUCTION LINE BETWEEN THE EVAPORATOR COIL AND THE COMPRESSOR FOR RETARDING LIQUIDS IN THE REFRIGERANT FLOWING FROM THE EVAPORATOR TO THE COMPRESSOR DURING DEFROSTING OPERATIONS, SAID UNIT COMPRISING A TANK SEALED AT BOTH ENDS BY CAP MEMBERS AND INCORPORATING FIRST AND SECOND BAFFLE MEMBERS THAT DIVIDE SAID TANK INTO A SEPARATION CHAMBER, A FLOW CONTROL CHAMBER AND A DISCHARGE CHAMBER, A HEAT EXCHANGER CHAMBER, WITH A DISCHARGE SEGMENT OF THE EVAPORATOR OUTLET LINE EXTENDING THERETO FOR DISCHARGING REFRIGERANT IN MINGLING LIQUID AND VAPOR FORM FROM THE EVAPORATOR THEREINTO, A DISCHARGE CHAMBER WITH AN INTAKE SEGMENT OF THE COMPRESSOR SUCTION LINE CONNECTED THEREIN; A METERING APERTURE ENCLOSED WITH A FINE MESH SCREEN MEMBER FOR PREVENTING THE INGRESS OF EXTRANEOUS MATTER THEREINTO FROM THE LOWERMOST REGION OF SAID SEPARATION CHAMBER, THE OUTLET OF WHICH IS SUPPORTED IN SAID FIRST BAFFLE MEMBER 